summaryrefslogtreecommitdiff
path: root/drivers/video/fbdev/core/syscopyarea.c
blob: 7b8bd3a2bedc50c5ca23cb180f52dd99229d9cfc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
/*
 *  Generic Bit Block Transfer for frame buffers located in system RAM with
 *  packed pixels of any depth.
 *
 *  Based almost entirely from cfbcopyarea.c (which is based almost entirely
 *  on Geert Uytterhoeven's copyarea routine)
 *
 *      Copyright (C)  2007 Antonino Daplas <adaplas@pol.net>
 *
 *  This file is subject to the terms and conditions of the GNU General Public
 *  License.  See the file COPYING in the main directory of this archive for
 *  more details.
 *
 */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/fb.h>
#include <asm/types.h>
#include <asm/io.h>
#include "fb_draw.h"

    /*
     *  Generic bitwise copy algorithm
     */

static void
bitcpy(struct fb_info *p, unsigned long *dst, unsigned dst_idx,
	const unsigned long *src, unsigned src_idx, int bits, unsigned n)
{
	unsigned long first, last;
	int const shift = dst_idx-src_idx;
	int left, right;

	first = FB_SHIFT_HIGH(p, ~0UL, dst_idx);
	last = ~(FB_SHIFT_HIGH(p, ~0UL, (dst_idx+n) % bits));

	if (!shift) {
		/* Same alignment for source and dest */
		if (dst_idx+n <= bits) {
			/* Single word */
			if (last)
				first &= last;
			*dst = comp(*src, *dst, first);
		} else {
			/* Multiple destination words */
			/* Leading bits */
 			if (first != ~0UL) {
				*dst = comp(*src, *dst, first);
				dst++;
				src++;
				n -= bits - dst_idx;
			}

			/* Main chunk */
			n /= bits;
			while (n >= 8) {
				*dst++ = *src++;
				*dst++ = *src++;
				*dst++ = *src++;
				*dst++ = *src++;
				*dst++ = *src++;
				*dst++ = *src++;
				*dst++ = *src++;
				*dst++ = *src++;
				n -= 8;
			}
			while (n--)
				*dst++ = *src++;

			/* Trailing bits */
			if (last)
				*dst = comp(*src, *dst, last);
		}
	} else {
		unsigned long d0, d1;
		int m;

		/* Different alignment for source and dest */
		right = shift & (bits - 1);
		left = -shift & (bits - 1);

		if (dst_idx+n <= bits) {
			/* Single destination word */
			if (last)
				first &= last;
			if (shift > 0) {
				/* Single source word */
				*dst = comp(*src << left, *dst, first);
			} else if (src_idx+n <= bits) {
				/* Single source word */
				*dst = comp(*src >> right, *dst, first);
			} else {
				/* 2 source words */
				d0 = *src++;
				d1 = *src;
				*dst = comp(d0 >> right | d1 << left, *dst,
					    first);
			}
		} else {
			/* Multiple destination words */
			/** We must always remember the last value read,
			    because in case SRC and DST overlap bitwise (e.g.
			    when moving just one pixel in 1bpp), we always
			    collect one full long for DST and that might
			    overlap with the current long from SRC. We store
			    this value in 'd0'. */
			d0 = *src++;
			/* Leading bits */
			if (shift > 0) {
				/* Single source word */
				*dst = comp(d0 << left, *dst, first);
				dst++;
				n -= bits - dst_idx;
			} else {
				/* 2 source words */
				d1 = *src++;
				*dst = comp(d0 >> right | d1 << left, *dst,
					    first);
				d0 = d1;
				dst++;
				n -= bits - dst_idx;
			}

			/* Main chunk */
			m = n % bits;
			n /= bits;
			while (n >= 4) {
				d1 = *src++;
				*dst++ = d0 >> right | d1 << left;
				d0 = d1;
				d1 = *src++;
				*dst++ = d0 >> right | d1 << left;
				d0 = d1;
				d1 = *src++;
				*dst++ = d0 >> right | d1 << left;
				d0 = d1;
				d1 = *src++;
				*dst++ = d0 >> right | d1 << left;
				d0 = d1;
				n -= 4;
			}
			while (n--) {
				d1 = *src++;
				*dst++ = d0 >> right | d1 << left;
				d0 = d1;
			}

			/* Trailing bits */
			if (m) {
				if (m <= bits - right) {
					/* Single source word */
					d0 >>= right;
				} else {
					/* 2 source words */
 					d1 = *src;
					d0 = d0 >> right | d1 << left;
				}
				*dst = comp(d0, *dst, last);
			}
		}
	}
}

    /*
     *  Generic bitwise copy algorithm, operating backward
     */

static void
bitcpy_rev(struct fb_info *p, unsigned long *dst, unsigned dst_idx,
	   const unsigned long *src, unsigned src_idx, unsigned bits,
	   unsigned n)
{
	unsigned long first, last;
	int shift;

	dst += (dst_idx + n - 1) / bits;
	src += (src_idx + n - 1) / bits;
	dst_idx = (dst_idx + n - 1) % bits;
	src_idx = (src_idx + n - 1) % bits;

	shift = dst_idx-src_idx;

	first = ~FB_SHIFT_HIGH(p, ~0UL, (dst_idx + 1) % bits);
	last = FB_SHIFT_HIGH(p, ~0UL, (bits + dst_idx + 1 - n) % bits);

	if (!shift) {
		/* Same alignment for source and dest */
		if ((unsigned long)dst_idx+1 >= n) {
			/* Single word */
			if (first)
				last &= first;
			*dst = comp(*src, *dst, last);
		} else {
			/* Multiple destination words */

			/* Leading bits */
			if (first) {
				*dst = comp(*src, *dst, first);
				dst--;
				src--;
				n -= dst_idx+1;
			}

			/* Main chunk */
			n /= bits;
			while (n >= 8) {
				*dst-- = *src--;
				*dst-- = *src--;
				*dst-- = *src--;
				*dst-- = *src--;
				*dst-- = *src--;
				*dst-- = *src--;
				*dst-- = *src--;
				*dst-- = *src--;
				n -= 8;
			}
			while (n--)
				*dst-- = *src--;
			/* Trailing bits */
			if (last != -1UL)
				*dst = comp(*src, *dst, last);
		}
	} else {
		/* Different alignment for source and dest */

		int const left = shift & (bits-1);
		int const right = -shift & (bits-1);

		if ((unsigned long)dst_idx+1 >= n) {
			/* Single destination word */
			if (first)
				last &= first;
			if (shift < 0) {
				/* Single source word */
				*dst = comp(*src >> right, *dst, last);
			} else if (1+(unsigned long)src_idx >= n) {
				/* Single source word */
				*dst = comp(*src << left, *dst, last);
			} else {
				/* 2 source words */
				*dst = comp(*src << left | *(src-1) >> right,
					    *dst, last);
			}
		} else {
			/* Multiple destination words */
			/** We must always remember the last value read,
			    because in case SRC and DST overlap bitwise (e.g.
			    when moving just one pixel in 1bpp), we always
			    collect one full long for DST and that might
			    overlap with the current long from SRC. We store
			    this value in 'd0'. */
			unsigned long d0, d1;
			int m;

			d0 = *src--;
			/* Leading bits */
			if (shift < 0) {
				/* Single source word */
				d1 = d0;
				d0 >>= right;
			} else {
				/* 2 source words */
				d1 = *src--;
				d0 = d0 << left | d1 >> right;
			}
			if (!first)
				*dst = d0;
			else
				*dst = comp(d0, *dst, first);
			d0 = d1;
			dst--;
			n -= dst_idx+1;

			/* Main chunk */
			m = n % bits;
			n /= bits;
			while (n >= 4) {
				d1 = *src--;
				*dst-- = d0 << left | d1 >> right;
				d0 = d1;
				d1 = *src--;
				*dst-- = d0 << left | d1 >> right;
				d0 = d1;
				d1 = *src--;
				*dst-- = d0 << left | d1 >> right;
				d0 = d1;
				d1 = *src--;
				*dst-- = d0 << left | d1 >> right;
				d0 = d1;
				n -= 4;
			}
			while (n--) {
				d1 = *src--;
				*dst-- = d0 << left | d1 >> right;
				d0 = d1;
			}

			/* Trailing bits */
			if (m) {
				if (m <= bits - left) {
					/* Single source word */
					d0 <<= left;
				} else {
					/* 2 source words */
					d1 = *src;
					d0 = d0 << left | d1 >> right;
				}
				*dst = comp(d0, *dst, last);
			}
		}
	}
}

void sys_copyarea(struct fb_info *p, const struct fb_copyarea *area)
{
	u32 dx = area->dx, dy = area->dy, sx = area->sx, sy = area->sy;
	u32 height = area->height, width = area->width;
	unsigned int const bits_per_line = p->fix.line_length * 8u;
	unsigned long *base = NULL;
	int bits = BITS_PER_LONG, bytes = bits >> 3;
	unsigned dst_idx = 0, src_idx = 0, rev_copy = 0;

	if (p->state != FBINFO_STATE_RUNNING)
		return;

	/* if the beginning of the target area might overlap with the end of
	the source area, be have to copy the area reverse. */
	if ((dy == sy && dx > sx) || (dy > sy)) {
		dy += height;
		sy += height;
		rev_copy = 1;
	}

	/* split the base of the framebuffer into a long-aligned address and
	   the index of the first bit */
	base = (unsigned long *)((unsigned long)p->screen_base & ~(bytes-1));
	dst_idx = src_idx = 8*((unsigned long)p->screen_base & (bytes-1));
	/* add offset of source and target area */
	dst_idx += dy*bits_per_line + dx*p->var.bits_per_pixel;
	src_idx += sy*bits_per_line + sx*p->var.bits_per_pixel;

	if (p->fbops->fb_sync)
		p->fbops->fb_sync(p);

	if (rev_copy) {
		while (height--) {
			dst_idx -= bits_per_line;
			src_idx -= bits_per_line;
			bitcpy_rev(p, base + (dst_idx / bits), dst_idx % bits,
				base + (src_idx / bits), src_idx % bits, bits,
				width*p->var.bits_per_pixel);
		}
	} else {
		while (height--) {
			bitcpy(p, base + (dst_idx / bits), dst_idx % bits,
				base + (src_idx / bits), src_idx % bits, bits,
				width*p->var.bits_per_pixel);
			dst_idx += bits_per_line;
			src_idx += bits_per_line;
		}
	}
}

EXPORT_SYMBOL(sys_copyarea);

MODULE_AUTHOR("Antonino Daplas <adaplas@pol.net>");
MODULE_DESCRIPTION("Generic copyarea (sys-to-sys)");
MODULE_LICENSE("GPL");